Okay, after a re-think;
Power, YEP! Even metric electrons are the same size
Software - what you learn today is obsolete the day before you can code in it.
I'd bet on a Java or it's future derivitive. At some point EVERY thing will be programmed with one SUPER code shell with a zillion compilers. Toaster,VCR,Robot,PDA - All will speak Farsi. Whatever Apple comes up with next will be the next "Gotta Have It"
When was the last time I coded in Fortran, Pascal, Lisp or Forth? All that time wasted learning them.
Device communication would be a very strong choice - new protocols will happen overnight. Find the start of the next wave crest - bleeding edge hurts, but then, Ya got to gamble.
A heck, just go for the money! Learn game software - pizza,Mountain Dew and a Porsche911.
And yes, I'm hands on. I still have my hands, otherwise I'd be designing my new GRIPPERS with a mouth stick. Shudder.
Hmm, keyboard - crescent wrench - hard choice
I'm working on my entropy machine, when I hit cycle start everything will be so cool - Rod